2. Description of Prior Art
This invention pertains generally to packing materials and, more particularly, to a system, method and material for making pneumatically filled packing cushions.
In order to reduce the amount of space required for shipment and storage, these air filled cushions are generally made at or near the point of use. Forming the perforations and seals and filling the cushions requires relatively complicated and expensive machines, and also requires a packer or shipper to undertake a more substantial manufacturing operation than he may want to.
Heretofore, there have been some attempts to reduce the complexity and cost of the machine which the packer or shipper must have by forming the perforations and some of the seals in the film material before it is shipped to him. Examples of such prefabricated materials are found in Ser. No. 09/488,621, filed Jan. 20, 2000. While those materials do permit simpler and less expensive machines to be used, there are still problems of getting the air into the cushions and getting the material sealed without losing the air so that the cushions will be inflated in a uniform and controllable manner.
It is in general an object of the invention to provide a new and improved system, method and material for making pneumatically filled packing cushions.
Another object of the invention is to provide a system, method and material of the above character which overcomes the limitations and disadvantages of the prior art.
These and other objects are achieved in accordance with the invention by providing a system, method and material for making pneumatically filled packing cushions in which a plastic film material having two superposed layers joined together along first and second longitudinal edges is processed at a first location by forming longitudinally spaced, transversely extending rows of perforations across it and sealing the two layers together along seal lines which extend from the first edge of the material in a direction generally parallel to the rows of perforations and terminate a short distance from the second edge of the material to form chambers with open mouths facing the second edge between the rows of perforations. The material is then fan-folded or formed into rolls for storage and shipment.
At a second location, gas is introduced into the chambers by passing the material along a tube positioned between the ends of the seals and the second edge of the material and injecting the gas into the open mouths of the chambers through openings in a side wall of the tube. The two layers are then sealed together across the open mouths to close the chambers and retain the gas in them.